1. Field of the Invention
The present invention relates to colored pigments based on a mineral oxide of the silica, alumina or titanium or zirconium oxide-type and to processes for the production thereof.
2. Description of the Prior Art
It is well known to this art, for numerous applications, to add mineral charges to a wide variety of different materials for purposes of imparting any given number of particular properties thereto. Among the most widely encountered such properties are optical, mechanical and rheological properties.
For certain applications, it is necessary to incorporate charges combined with a pigment or dye. Generally, these charge/pigment compositions are produced by physically admixing the mineral charge with the dye or pigment. However, such process suffers from a certain number of disadvantages.
A first disadvantage is that it is difficult for a given mineral charge to contain all of the desired coloration.
Another problem is linked to the compatibility of the dye with the material intended to be provided with the pigmentation. Therefore, for a given material, as a function of said compatibility, it will only be possible to use a limited number of dyes or pigments. It is also necessary to take account of the dispersibility of the dye in the same material.
Moreover, the resulting colored compositions can display a low resistance to chemical and photochemical deterioration, as well as to abrasion.